diff options
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/pda.h | 3 | ||||
| -rw-r--r-- | arch/x86/include/asm/percpu.h | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/processor.h | 23 | ||||
| -rw-r--r-- | arch/x86/include/asm/stackprotector.h | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/system.h | 4 |
5 files changed, 27 insertions, 15 deletions
diff --git a/arch/x86/include/asm/pda.h b/arch/x86/include/asm/pda.h index b473e952439a..ba46416634f0 100644 --- a/arch/x86/include/asm/pda.h +++ b/arch/x86/include/asm/pda.h @@ -17,9 +17,6 @@ struct x8664_pda { unsigned long unused4; int unused5; unsigned int unused6; /* 36 was cpunumber */ - unsigned long stack_canary; /* 40 stack canary value */ - /* gcc-ABI: this canary MUST be at - offset 40!!! */ short in_bootmem; /* pda lives in bootmem */ } ____cacheline_aligned_in_smp; diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index 165d5272ece1..ce980db5e59d 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -133,12 +133,6 @@ do { \ /* We can use this directly for local CPU (faster). */ DECLARE_PER_CPU(unsigned long, this_cpu_off); -#ifdef CONFIG_X86_64 -extern void load_pda_offset(int cpu); -#else -static inline void load_pda_offset(int cpu) { } -#endif - #endif /* !__ASSEMBLY__ */ #ifdef CONFIG_SMP diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index f511246fa6cd..48676b943b92 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -379,8 +379,29 @@ union thread_xstate { #ifdef CONFIG_X86_64 DECLARE_PER_CPU(struct orig_ist, orig_ist); -DECLARE_PER_CPU(char[IRQ_STACK_SIZE], irq_stack); +union irq_stack_union { + char irq_stack[IRQ_STACK_SIZE]; + /* + * GCC hardcodes the stack canary as %gs:40. Since the + * irq_stack is the object at %gs:0, we reserve the bottom + * 48 bytes of the irq stack for the canary. + */ + struct { + char gs_base[40]; + unsigned long stack_canary; + }; +}; + +DECLARE_PER_CPU(union irq_stack_union, irq_stack_union); DECLARE_PER_CPU(char *, irq_stack_ptr); + +static inline void load_gs_base(int cpu) +{ + /* Memory clobbers used to order pda/percpu accesses */ + mb(); + wrmsrl(MSR_GS_BASE, (unsigned long)per_cpu(irq_stack_union.gs_base, cpu)); + mb(); +} #endif extern void print_cpu_info(struct cpuinfo_x86 *); diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h index 2383e5bb475c..36a700acaf2b 100644 --- a/arch/x86/include/asm/stackprotector.h +++ b/arch/x86/include/asm/stackprotector.h @@ -2,7 +2,7 @@ #define _ASM_STACKPROTECTOR_H 1 #include <asm/tsc.h> -#include <asm/pda.h> +#include <asm/processor.h> /* * Initialize the stackprotector canary value. @@ -19,7 +19,7 @@ static __always_inline void boot_init_stack_canary(void) * Build time only check to make sure the stack_canary is at * offset 40 in the pda; this is a gcc ABI requirement */ - BUILD_BUG_ON(offsetof(struct x8664_pda, stack_canary) != 40); + BUILD_BUG_ON(offsetof(union irq_stack_union, stack_canary) != 40); /* * We both use the random pool and the current TSC as a source @@ -32,7 +32,7 @@ static __always_inline void boot_init_stack_canary(void) canary += tsc + (tsc << 32UL); current->stack_canary = canary; - write_pda(stack_canary, canary); + percpu_write(irq_stack_union.stack_canary, canary); } #endif diff --git a/arch/x86/include/asm/system.h b/arch/x86/include/asm/system.h index b77bd8bd3cc2..52eb748a68af 100644 --- a/arch/x86/include/asm/system.h +++ b/arch/x86/include/asm/system.h @@ -89,10 +89,10 @@ do { \ #ifdef CONFIG_CC_STACKPROTECTOR #define __switch_canary \ "movq %P[task_canary](%%rsi),%%r8\n\t" \ - "movq %%r8,%%gs:%P[pda_canary]\n\t" + "movq %%r8,%%gs:%P[gs_canary]\n\t" #define __switch_canary_param \ , [task_canary] "i" (offsetof(struct task_struct, stack_canary)) \ - , [pda_canary] "i" (offsetof(struct x8664_pda, stack_canary)) + , [gs_canary] "i" (offsetof(union irq_stack_union, stack_canary)) #else /* CC_STACKPROTECTOR */ #define __switch_canary #define __switch_canary_param |